Effect of starting materials on the superconducting properties of SmFeAsO1-xFx tapes

TL;DR

This study investigates how different starting materials affect the impurity phases, structure, and superconducting performance of SmFeAsO1-xFx tapes, finding optimal materials that maximize critical current density and zero-resistivity temperature.

Contribution

It demonstrates that specific starting materials lead to improved superconducting properties and record Jc values in SmFeAsO1-xFx tapes.

Findings

Optimal starting materials reduce impurity phases.

Denser structure with better grain connectivity.

Highest reported Jc of ~4600 A/cm^2 at 4.2 K.

Abstract

SmFeAsO1-xFx tapes were prepared using three kinds of starting materials. It shows that the starting materials have an obvious effect on the impurity phases in final superconducting tapes. Compared with the other samples, the samples fabricated by SmAs, FeO, Fe2As, and SmF3 have the smallest arsenide impurity phase and voids. As a result, these samples possess much denser structure and better grain connectivity. Moreover, among the three kinds of samples fabricated in this work, this kind of sample has the highest zero-resistivity temperature ~40 K and largest critical current density ~4600 A/cm^2 in self-field at 4.2 K. This is the highest Jc values reported so far for SmFeAsO1-xFx wires and tapes.